The £3,500 sum CUSU budgeted to pay this year in fees for National Union of Students (NUS) conferences is absent from official guidance, produced by CUSU’s Elections Committee, about the ongoing referendum.

There are also a striking discrepancy between the official guidance and the CUSU budget for 2015/16, concerning the amount CUSU paid NUS in affiliation fees, Varsity can reveal.

The “contextual information” for voters says “CUSU paid £250 in affiliation fees to NUS for the year 2015/16”. It does not mention the separate “Conferences” fees which CUSU pays NUS, which stood at £3,500 for the past year.

The contextual information is designed to outline the basics of CUSU’s relationship with NUS, and provide clear and essential facts about the financial relationship between the two bodies.

The incomplete information appears on referendum posters across Cambridge, and on CUSU’s website.

The revelation marks a new twist in what has already been a controversial voting period.

Analysis of CUSU’s recent budgets reveals a wide disparity between the amount referendum guidance says was paid to NUS, and how much was budgeted.

While the £250 affiliation figure is in line with what CUSU have budgeted for 2016/17, the budget for 2015/16 shows that £6,000 was assigned to NUS affiliation fees.

Taken together, the unlisted costs from the budget represent £9,250 of payments to NUS absent from the contextual information.

The £250 figure budgeted for 2016/17, which is the minimum affiliation fee NUS charge, is far less than the amounts which have been budgeted in recent years. Between 2012/13 and 2015/16, CUSU budgeted between £6,000 and £8,000 for the annual costs of affiliating to NUS.

It is unknown whether the £250 affiliation rate – which is typically based upon the number of students a student union serves and its grant – will be sustained, or if it could rise again in coming years.

While the projected £3,500 in conference fees from this year are omitted from the contextual information, other financial particulars of CUSU’s relationship with NUS are detailed. These include that “CUSU currently earns £13,500 from the sale of NUS Extra Cards to Cambridge students” and that the CUSU website’s use of an NUS platform “currently costs around £10,000 per year”. The website carries adverts, including ones for NUS products, and is said to “generate revenue”.

The amount CUSU pays NUS in conference fees has fluctuated markedly over the years according to previous budgets, rising from £900 in 2012/13, to £1,500 in 2013/14 and 2014/15, to its current high of £3,500 this academic year.

Speaking to Varsity, the 'Yes' to disaffiliation campaign’s Adam Crafton said: “It's disappointing that CUSU provided inaccurate financial estimates of the consequences of disaffiliation in their contextual information.

“We know that this 'neutral' information has been sent in good faith by JCR and MCR Presidents but I seriously hope that votes were not cast with these financial forecasts in mind.

“On Thursday evening, we sent three emails to the Election Committee asking for an urgent clarification. We received no reply. Hopefully the Elections Committee will apologise for this oversight.”

Jemma Stewart of Elections Committee told Varsity the absence of the figures has been “an oversight on the part of Elections Committee”. She added that “The relevant information has been added to the contextual information on the CUSU website, and we will be emailing students today to inform them of the vote along with the contextual information”.

Stewart sent out an email to students shortly afterwards, which said “We have added some extra information to the contextual information today”.

“We have had a remarkable turnout of over 5,500 students having their say in the referendum already”, the email added.

The contextual data has been updated in response to the discrepencies Varsity revealed. It now says “Between 2012-15, NUS offered a rolling hardship to CUSU in recognition that CUSU's funding model did not fit well with NUS' method for calculating affiliation”, and that “Due tot he [sic] uncertainty of these changes, CUSU prudently budgeted for higher affiliation fees in the event that NUS amended its affiliation model in a manner that required greater expense”.

The contextual data also includes information about conference fees, saying: “It is common for CUSU to meet the travel and accommodation expenses of students attending conferences, where those students have been duly elected from their membership. In 2015-16, CUSU spent £3000 on sending students to National Conferences.”

Reacting to the emails, Adam Crafton said “CUSU should have sent out an email that clearly directed the electorate to the grave miscalculations they made in their original 'neutral' information. Instead, it's almost been airbrushed into a cheery-chappy email in the penultimate sentence of the third paragraph. If they really had any interests in leading a fair referendum, an appropriate email would have been distributed that clearly sought to alert the attention of voters to the true nature of the financial situation.”

The referendum, which will determine whether the University of Cambridge remains affiliated with the NUS, will end at 4pm today.